Such is their festival cachet, Joel and Ethan Coen would be feted at a film shindig in Pyongyang. Cannes, needless to say, is a cinch for them. The pair will have assembled cineastes eating out of their hands when they debut Inside Llewyn Davis, their latest, on the Med. It’s a period piece set during Greenwich Village’s folk heyday – Oscar Isaac plays the titular folkster – that Cannesgoers will see long before its January 2014 release. On the upside, it gives the rest of us seven months before the folk revival hits.